Corresponding Parts and Scale Factor

Corresponding Parts and Scale Factor

Learning Target: I can describe characteristics of scaled copies.

What are corresponding parts?

• When part of an original figure matches up with part of a copy, we call them corresponding parts. 

• These could be points, segments, angles, or distances.

Whole Class Example

What letters corresponds to the line AC?
What point corresponds to the point B?
What angle corresponds to the <ACB?

Multiple Choice

What are corresponding parts?

• lines, points, and angles that are the same value or place on a shape

• parts of a square

• parts of a triangle

• another word for the perimeter of a shape

Multiple Choice

Find the corresponding part to point B.

• Point Z

• Point C

• Point Y

• Point X

Multiple Choice

Find the corresponding part to line segment ML

• Line Segment ST

• Line Segment JK

• Line Segment RS

• Line Segment UT

STOP HERE FOR TODAY!

STUDENTS NEED TO

1. Complete Exit Slip on Google Classroom - https://forms.gle/Nika2pmW8iJnH7yS6
2. Work on IXL J.1-J.4 should be completed by FRIDAY!!!

What is scale factor?

• To create a scaled copy, we multiply all the lengths in the original figure by the same number. 

• The number you multiply by is the scale factor

• You can find the scale factor by using ratios

• The scale factor is the ratio of corresponding side lengths

Multiple Select

What does scale factor mean?

• the number you multiply by to create a new shape

• the size of the angles

• a ratio between corresponding side lengths

• the sum of all the side lengths

Scale Factor Whole Class Example 

• What is the scale factor from shape A to shape B?

• Find the corresponding sides and create two fractions

• 2/6 and 8/24

• Use cross products or find the missing multiplier!

Multiple Choice

Find the scale factor

• multiply by 1

• multiply by 2

• multiply by 3

• multiply by 4

Whole Class Example: Finding Scale Factor and Missing Number 

• locate corresponding side lengths

• look for relationships between their numbers

• How many centimetres is the side length GF?

• What is the scale factor?

Multiple Choice

How long is the side length GE?

• multiply by 7

• 35 cm

• 28 cm

• 42 cm

Multiple Choice

How long is side length s?

• 15

• 12

• 9

• 3

Open Ended

Tell me one thing you learned in class this week!